The present invention relates to a thermosetting resin composition. In particular, the present invention relates to a thermosetting resin composition which is suitably used for protective layers, electric insulation coatings and the like for electric appliances, electronic devices and the like. The present invention also relates to a modified carbodiimide resin which is suitably used as a component of the aforementioned thermosetting resin composition.
As such a thermosetting resin composition as mentioned above, there have been known, for example, thermosetting resin compositions containing one or more kinds of organic polyisocyanates, one or more kinds of organic monoisocyanates, one or more kinds of crosslinking agents having two or more active hydrogen groups in a molecule thereof, and one or more kinds of catalysts promoting carbodiimidation of the isocyanates such as those described in Japanese Patent Publication No. 5-6564 (1993), and thermosetting resin compositions characterized in that they contain (A) a resin which is composed of a polycarbodiimide containing a repeating unit represented by the general formula --N.dbd.C.dbd.N--R.sup.1 -- wherein R.sup.1 represents a divalent organic group, on which one or more kinds of compounds having a group causing grafting reaction and a carboxylic acid anhydride group are grafted, and (B) an epoxy compound such as those disclosed in Japanese Patent Application Laid-Open No. 8-81545 (1996).
However, an adhesive property and resistance to humidity after curing of such thermosetting resin compositions as those disclosed in Japanese Patent Publication No. 5-6564 (1993) have room for improvement, though they are excellent in heat resistance after curing. Further, such thermosetting resin compositions as those disclosed in Japanese Patent Application Laid-Open No. 8-81545 (1996) requires strict moisture content control because they have acid anhydride groups, and disadvantageously takes a long period of time for the reaction with the epoxy resin.